HYDRAULIC – Air – DGCA Question Bank For Politics

#1. Modern aircraft hydraulic systems use?

Mineral based fluid.

Synthetic fluids.

Alcohol based fluids.

Vegetable based fluids.

#2. A shuttle valve is used to?

Switch from one supply to another.

Switch from one service to another .

Operate components in sequence.

Move components backwards and forwards.

#3. One of the reasons for pressurising hydraulic reservoirs is to?

Prevent pump cavitation.

Prevent the collection of bubbles in the reservoir.

Prevent the ingress of moisture into the fluid.

Reduce the pressure rise necessary in the pump.

#4. Hydraulic reservoirs are pressurised?

By ground crew before flight.

Using air from the air conditioning packs.

Using engine bleed air from gas turbine engines.

Uses a dedicated air compressor unit.

#5. A hydraulic fuse?

Minimises loss of fluid in the event of a hose failure.

Prevent excessive fluid flow rates when jacks become unloaded.

limits the rate at which services operate.

Permits gravity lowering of landing gear.

#6. In addition to collecting excess fluid from the system, a hydraulic reservoir also?

Relieves excessive pressures.

Prevent pressure surges.

Minimises the amount of fluid that must be carried.

Keeps fluid up to working temperature.

#7. Hydraulic systems operate on the principles of............. pressure and ........... jack displacements?

Low small.

Low large.

High small.

High large.

#8. Hydraulic reservoirs are pressurised in order to?

Prevent foaming of fluid.

Prevent freezing of fluid.

Maintain constant supply when inverted.

Minimise pressure rise necessary in pumps.

#9. Mineral based hydraulic fluid is ……..and must be used with ......... seals?

Purple ,synthetic rubber.

Red , synthetic rubber.

Blue , natural rubber.

Green , natural rubber.

#10. What services can be operated by the RAT? 1. Landing gear. 2. Flaps. 3. Flying controls. 4. Spoilers.

1,2,3.

2,3,4.

1,2,4.

All of the above.

#11. . If compressed air is used to operate a hydraulic system in an emergency, it will use a?

Tilt valve.

Rotary valve.

Slide valve.

Shuttle valve.

#12. What force must be applied to piston b to balance the system below?

0.5 N.

50 N.

500 N.

5000 N.

#13. What force must be applied to piston b to balance the system below?

25 N.

50 N.

100 N.

125 N.

#14. The RAT supplies?

Nosewheel steering.

Flaps.

Landing gear.

Primary flight controls.

#15. Modern transport aircraft hydraulic systems typically use?

1000 to 2000 psi.

2000 to 3000 psi.

3000 to 4000 psi.

4000 to 5000 psi.

#16. If a hydraulic accumulator is charged with air to a pressure of 1200 psi, what will its pressure gauge show when the system hydraulic pump is running to supply 3000 psi to the system?

1200 psi.

2400 psi.

3000 psi.

4200 psi.

#17. In addition to storing energy, hydraulic accumulators also?

Minimise fluid leaks.

Minimise fluid required.

Reduce pressure fluctuations.

Reduce the size of reservoir required.

#18. Hydraulic reservoirs are pressurised in order to ?

Prevent pump cavitation.

Prevent freezing of fluid.

Keep fluid cool.

Prevent ingress of moisture.

#19. Synthetic hydraulic fluid is coloured?

Red.

Blue.

Orange.

Yellow.

#20. What will the gauge in the system below indicate?

300 psi.

600 psi.

3000 psi.

15000 psi.

#21. The valve on the right is used to?

Prevent expansion of flow.

Control flow rate.

Limit fluid loss through leaks.

Relieve excess pressure.

#22. Hydraulic fluid must be?

Effectively incompressible over the working pressure range of the system.

Able to absorb water readily.

Low boiling point and flash point.

Low lubricity and viscosity.

#23. The valve on the right is used to?

control system pressure.

Limit fluid loss due to leaks.

Control the movement of actuators.

Control system pressure.

#24. A hydraulic accumulator is charged to 1500 psi. if the system is then pressurised to 3000 psi the accumulator gauge will read?

1500 psi.

2000 psi.

3000 psi.

2500 psi.

#25. The stack pipe in a hydraulic reservoir?

Feeds the emergency services.

Feeds all of the systems.

Feeds the normal system but reserves fluid for the emergency systems.

Prevents debris from circulating in the system.

#26. Hydraulic fluid with a milky appearance?

Is normal after flight.

Indicate aeration of the system and should be investigated.

Indicates aeration but is quite normal.

Indicates water in the system, the fluid must be changed.

#27. The vent in a non-pressurised hydraulic reservoir?

Prevent pump cavitation.

Prevent the ingress of water vapour.

Prevent the creation of partial vacuums and over-pressures in the reservoir.

Prevent the fluid from boiling.

#28. Item A in the diagram is ?

A vent.

A stack pipe.

An emergency system supply line.

A return line.

#29. The component which directs fluid to and from an actuator is a?

Return valve.

Non-return valve.

Selector valve.

Hydraulic fuse.

#30. A hydraulic fuse?

Prevents reverse fluid flows.

Controls fluid flow rates.

Minimises fluid leakage.

Ruptures if fluid flow becomes excessive.

#31. Item B in the diagram is?

A vent.

A stack pipe.

An emergency system supply line.

A return line.

#32. A hydraulic fuse is fitted?

Downstream of non-essential services.

Downstream of essential services.

Upstream, of essential services.

Upstream of non-essential services.

#33. The component illustrated is a?

Hydraulic filter.

Bobbin filter.

Hydraulic fuse.

Non-return valve.

#34. An ACOV?

Provides an idle circuit for a constant delivery pump.

Provides an idle circuit for a variable delivery pump.

Controls pump output pressure.

Controls pump output flow.

#35. If the accumulator is charged to 1000 psi and the system is then operated at 3000 psi, the cockpit gauge will read .......... and the accumulator gauge will read?

1000 psi 1000 psi.

1000 psi 3000 psi.

3000 psi 3000 psi.

4000 psi 4000 psi.

#36. The output of a constant delivery pump is?

Constant.

Determined by swash plate angle.

Controlled by a servo piston.

Proportional to RPM.

#37. What is the cracking pressure of a full flow relief valve if system pressure is 3000 psi and the valve is fully open at 3300 psi?

2700 psi.

3000 psi.

3190 - 3300 psi.

3300 psi.

#38. Item C in the diagram is ?

A vent .

A stack pipe.

An emergency system supply line.

A return line.

#39. Modern aircraft hydraulic systems operate on the principle of?

High pressure large displacement.

High pressure small displacement.

High pressure large actuators.

Low pressure small actuators.

#40. Thermal expansion, jack ram displacement and small leaks are allowed for by the?

Reservoir.

Accumulator.

Check valves.

Pressure relief valves.

#41. Hydraulic pressure pulsations and fluctuations when systems are selected, are smoothed out by?

Accumulator.

Swash plate pumps.

ACOV.

Pressure relief valves.

#42. If a shuttle valve sticks in the normal position?

Normal system actuation will be impossible.

Emergency system actuation will be impossible.

System operation will be impossible.

The system will operate sluggishly.

#43. A shuttle valve?

Controls the direction of motion of hydraulic actuators.

Controls the pressure sources of hydraulic systems.

Shuts off the normal supply and connects the emergency supply when emergency operation is selected by the pilot.

Automatically selects the emergency supply whenever the main supply fails.

#44. At start up the swash plate in a variable delivery hydraulic pump is at?

Maximum angle to build up pressure.

Minimum angle to assist starting.

Flat pitch because there is no pressure on its servo piston.

Whatever angle it was at prior to shut down.

#45. If the small piston is pushed down 10 cm, the large piston will?

Go down 10 cm.

Go up 10 cm.

Go down 5 cm.

Go up 5 cm.

#46. If a hydraulic accumulator does not have a pressure gauge, its nitrogen charge pressure can be tested?

Only by fitting a maintenance test gauge.

By exercising the system with the pump stopped, and observing the pressure indication immediately before it falls suddenly to zero.

By applying the brakes fully and observing the brake pressure gauge indication.

Only by discharging it and recharging with new nitrogen.

#47. A high pressure hydraulic pump?

Sucks in fluid from the reservoir.

Must be provided with a positive feed of fluid.

Requires no cooling flow.

Requires an ACOV.

#48. A pressure maintaining valve?

Maintains pressure for essential services following fluid loss.

Controls maximum system pressure.

Maintains system pressure after shut down.

Provides a positive supply of fluid to the pump.

#49. Low hydraulic accumulator charge pressure is likely to cause?

chattering and pressure fluctuations.

Slow operations of services.

Unusually fast operation of services.

Inability to operate services in flight.

#50. The valve illustrated is used to?

Reduce operation rate in one direction.

Prevent inadvertent operation.

Reduce fluid flow in both direction.

Operate service in correct sequence.

#51. Thermal relief valves?

Allow for thermal expansion of fluid.

Allow for thermal contraction of fluid.

Allow for thermal expansion and contraction of fluid.

Release over heated fluid from the system.

#52. A hydraulic fuse would be fitted?

Upstream of essential services.

Upstream of all services.

Upstream of non essential services.

Downstream of all services.

#53. A hydraulic RAT is used to power?

Landing gear.

Brakes.

Flying controls.

All hydraulic services.

#54. The completion of one part of an operation before the commencement of another is ensured by?

NRVs.

Sequence valves.

Spill valves.

Pressure raising valves.

#55. Excessive gear extension rates are prevented by?

One way restrictors in the down lines.

One way restrictors in the up lines.

Sequence valves.

Rate of operation limiting valves.

#56. An emergency hydraulic hand pump draws its fluid supply from?

The bottom of the reservoir.

The stack pipe.

The return lines.

A separate reservoir.

#57. Non essential hydraulic services draw their fluid supply from?

The bottom of the reservoir.

The stack pipe.

The return lines.

A separate reservoir.

#58. An indication of hydraulic fluid specification can be provided?

Only by the labels on the container in which it is supplied.

By its colour.

By its smell.

By its taste.

#59. A full flow relief valve is most commonly located?

Upstream of the pump.

Between the pump and filter.

Between the pump and reservoir.

In the return lines.

#60. The valve illustrated is used with?

Constant pressure pump.

Constant delivery pump.

Swash plate pump.

Hand pump.

#61. Phosphate ester based (SKYDROL) hydraulic system seals are?

Natural rubber.

Polyethylene.

Butyl rubber.

Neoprene.

#62. Hydraulic system back pressure is?

Pressure of the gas in the accumulator.

Pressure exerted by the loads resisting the motion of the jacks.

Pressure generated by the rate of motion of the system.

Pressure employed to resist excessive rates of motion in the system.

#63. Hydraulic system hammering?

Is caused by sticking jacks in is quite normal.

Is caused by the ACOV and is quite normal.

Is caused by entrapped air and can cause pipe fracture if left uncorrected.

Is caused by defective swash plate pump servo pistons.

#64. Fluid available to the engine driven pump is normally?

Unfiltered.

That between the fluid level and the bottom of the stack pipe.

That between the fluid level and the bottom of the reservoir.

That above the top of the stack pipe.

#65. A variable delivery constant pressure pump is

Set to minimum output prior to start up.

Set to maximum stroke prior to start up.

Goes to maximum stroke during shut down.

A constant stroke device.

#66. If the ACOV in a constant delivery hydraulic system fails in the closed position?

Pressure will fall to zero.

Pressure will remain constant.

Pressure will increase until the relief valve opens.

Pressure will increase until the pipes burst or the system is shut down.

#67. Shuttle valves?

Permit two separate power sources to operate one service.

Permit one power source to operate a number of services.

Prevent reverse flow of fluid.

Carry used fluid back to the reservoir.

#68. A hydraulic system pressure gauge indicates?

Fluid pressure.

Accumulator gas pressure.

Fluid pressure plus accumulator gas pressure.

Pump output pressure.

#69. A double acting hand pump?

Is two pumps in series.

Is two pumps in parallel.

Provides pressure on both the in and out strokes.

Provides pressure only on the in stroke.

#70. When the system in the diagram is pressurised the jack will?

Move left.

Move right.

Not move.

Move left or right Depending on pressure.

#71. Which of the following statements are true of a open centre hydraulic system? 1. It is simple. 2. when services are not being used, the pump is off loaded by sending the fluid back to the reservoir. 3. it can operate many services simultaneously. 4. The pump requires no cooling flow in the off loaded condition. 5. It is used in most large aircraft.

1,3,4,5.

2,5.

1,2.

1,3,4,5.

#72. Which of the following statements are true of a closed centre hydraulic system? 1. Pressure is almost constant in the centre of the system. 2. When services are not being used, the pump is off loaded by sending the fluid back to the reservoir. 3. It can operate many services simultaneously. 4. The pump requires no cooling flow in the off loaded condition. 5. It is used in most large aircraft.

1,3,5.

1,2,4.

2,3,5.

3,4,5.

#73. Which of the following statements are true of the jack illustrated? 1. It is a balanced, double acting type. 2. It is lighter than a single acting type. 3. It affects the reservoir fluid level. 4. Force is the same in both directions.

2,3.

1,4.

3,4.

2,4.

#74. A pressure maintaining valve?

Control pump swash plate angle to maintain constant system pressure.

Maintains constant pressure available for high priority services even if this prevents lower priority service from operating.

Prevents low priority services from operating when higher priority services are in use.

Maintains constant system pressure regardless of demand.

#75. A hydraulic lock?

Is used to prevent gear retraction from being selected when on the ground.

Prevents jack movement when services are selected.

Prevent jack movement when the selectors are in neutral.

Is a means of limiting fluid loss following pipe fracture.

Dgca Question Bank For Pilots

Results

#1. Modern aircraft hydraulic systems use?

#2. A shuttle valve is used to?

#3. One of the reasons for pressurising hydraulic reservoirs is to?

#4. Hydraulic reservoirs are pressurised?

#5. A hydraulic fuse?

#6. In addition to collecting excess fluid from the system, a hydraulic reservoir also?

#7. Hydraulic systems operate on the principles of............. pressure and ........... jack displacements?

#8. Hydraulic reservoirs are pressurised in order to?

#9. Mineral based hydraulic fluid is ……..and must be used with ......... seals?

#10. What services can be operated by the RAT? 1. Landing gear. 2. Flaps. 3. Flying controls. 4. Spoilers.

#11. . If compressed air is used to operate a hydraulic system in an emergency, it will use a?

#12. What force must be applied to piston b to balance the system below?

#13. What force must be applied to piston b to balance the system below?

#14. The RAT supplies?

#15. Modern transport aircraft hydraulic systems typically use?

#16. If a hydraulic accumulator is charged with air to a pressure of 1200 psi, what will its pressure gauge show when the system hydraulic pump is running to supply 3000 psi to the system?

#17. In addition to storing energy, hydraulic accumulators also?

#18. Hydraulic reservoirs are pressurised in order to ?

#19. Synthetic hydraulic fluid is coloured?

#20. What will the gauge in the system below indicate?

#21. The valve on the right is used to?

#22. Hydraulic fluid must be?

#23. The valve on the right is used to?

#24. A hydraulic accumulator is charged to 1500 psi. if the system is then pressurised to 3000 psi the accumulator gauge will read?

#25. The stack pipe in a hydraulic reservoir?

#26. Hydraulic fluid with a milky appearance?

#27. The vent in a non-pressurised hydraulic reservoir?

#28. Item A in the diagram is ?

#29. The component which directs fluid to and from an actuator is a?

#30. A hydraulic fuse?

#31. Item B in the diagram is?

#32. A hydraulic fuse is fitted?

#33. The component illustrated is a?

#34. An ACOV?

#35. If the accumulator is charged to 1000 psi and the system is then operated at 3000 psi, the cockpit gauge will read .......... and the accumulator gauge will read?

#36. The output of a constant delivery pump is?

#37. What is the cracking pressure of a full flow relief valve if system pressure is 3000 psi and the valve is fully open at 3300 psi?

#38. Item C in the diagram is ?

#39. Modern aircraft hydraulic systems operate on the principle of?

#40. Thermal expansion, jack ram displacement and small leaks are allowed for by the?

#41. Hydraulic pressure pulsations and fluctuations when systems are selected, are smoothed out by?

#42. If a shuttle valve sticks in the normal position?

#43. A shuttle valve?

#44. At start up the swash plate in a variable delivery hydraulic pump is at?

#45. If the small piston is pushed down 10 cm, the large piston will?

#46. If a hydraulic accumulator does not have a pressure gauge, its nitrogen charge pressure can be tested?

#47. A high pressure hydraulic pump?

#48. A pressure maintaining valve?

#49. Low hydraulic accumulator charge pressure is likely to cause?

#50. The valve illustrated is used to?

#51. Thermal relief valves?

#52. A hydraulic fuse would be fitted?

#53. A hydraulic RAT is used to power?

#54. The completion of one part of an operation before the commencement of another is ensured by?

#55. Excessive gear extension rates are prevented by?

#56. An emergency hydraulic hand pump draws its fluid supply from?

#57. Non essential hydraulic services draw their fluid supply from?

#58. An indication of hydraulic fluid specification can be provided?

#59. A full flow relief valve is most commonly located?

#60. The valve illustrated is used with?

#61. Phosphate ester based (SKYDROL) hydraulic system seals are?

#62. Hydraulic system back pressure is?

#63. Hydraulic system hammering?

#64. Fluid available to the engine driven pump is normally?

#65. A variable delivery constant pressure pump is

#66. If the ACOV in a constant delivery hydraulic system fails in the closed position?

#67. Shuttle valves?

#68. A hydraulic system pressure gauge indicates?

#69. A double acting hand pump?

#70. When the system in the diagram is pressurised the jack will?

#73. Which of the following statements are true of the jack illustrated? 1. It is a balanced, double acting type. 2. It is lighter than a single acting type. 3. It affects the reservoir fluid level. 4. Force is the same in both directions.

#74. A pressure maintaining valve?

#75. A hydraulic lock?